A computer network is a collection of interconnected network devices that can exchange data and share resources. Network devices within computer networks often include a control unit that provides control plane functionality and forwarding components for routing or switching data units. In some cases, for example, a network device may include a plurality of packet forwarding engines (PFEs) and a switch fabric that collectively provide a forwarding plane for forwarding network traffic. The control unit maintains routing information in a routing information base (RIB) that represents the overall topology of the network and defines routes to destinations within the network. The control unit derives a forwarding information base (FIB) that includes a number of forwarding data structures in accordance with the routing information. In some cases, the control unit may install the forwarding data structures into each of the PFEs to update copies of the FIB within each of the PFEs and control traffic forwarding within the forwarding plane.
As one example of a computer network, a service provider network typically provides one or more services that involve communicating data over the Internet. For customers that require high-availability in accessing either the public network or other services offered by the service provider, the customer may require a redundant connection to the service provider network. This redundant connection may involve coupling the customer's network device that resides at the edge of the customer network, such as a customer edge (CE) router, to a provider edge (PE) router of the service provider network that is different than a primary PE router to which the CE router is coupled via a primary connection. The redundant connections are typically not actively used for data transmission, but may be used as a backup forwarder in the event of a network failure that would preclude the primary PE router from sending the data. As a result, the primary connection may be referred to as the active connection while the redundant connection may be referred to as the non-active or backup connection. Having multiple connections between the CE router and the PE routers may commonly be referred to as “multi-homing.”